Biochemical assay methods

Abstract

Biochemical Assay Methods. There is described a method for determining a value that allows the effect that a compound has on a target to be compared with the effect that another compound has on the target, which method comprises adding the compound, at a concentration which continuously varies with time, to a flow of the target. The method can be carried out using a microfluidic system.

1 . A method for determining a value that allows the effect that a compound has on a target to be compared with the effect that another compound has on the target, which method comprises adding the compound, at a concentration which continuously varies with time, to a flow of the target. 
   
   
       2 . A method according to  claim 1  wherein the value is the IC x  value or EC x  value of the compound, wherein x is a percentage of the target activity. 
   
   
       3 . A method according to  claim 1  wherein the continuous variation of the compound concentration with time is achieved by keeping the overall flow rate constant whilst changing the flow rate of the compound and/or the target. 
   
   
       4 . A method according to  claim 3  wherein the continuous variation of the compound concentration with time is achieved by changing the flow rate of the compound whilst changing the flow rate of a component other than the target so as to keep the overall flow rate constant. 
   
   
       5 . A method according to  claim 1  comprising more than one step of adding the compound to a flow of the target and wherein the concentration of the compound varies continuously with time throughout each of these steps and wherein the rate of change of compound concentration with respect to time in each step is different from the rate of change of compound concentration with respect to time in any of the other steps and/or the compound concentration range in each step is different from the compound concentration range in any of the other steps. 
   
   
       6 . A method according to  claim 5  in which, within each step, the rate of change of compound concentration with respect to time is constant. 
   
   
       7 . A method according to  claim 5  in which the rate of change of compound concentration with time differs between each step. 
   
   
       8 . A method according to  claim 5  in which the rate of change of compound concentration with time is the same in each step. 
   
   
       9 . A method according to  claim 5  in which:
 the difference between the compound concentration at the beginning and end of the step, divided by the compound concentration at the beginning of the step is the same in each step.   
   
   
       10 . A method according to  claim 5  in which each step is performed for the same length of time. 
   
   
       11 . A method according to  claim 5  in which:
 the difference between the compound concentration at the beginning and end of the step, divided by the compound concentration at the beginning of the step is the same in each step; and   each step is performed for the same length of time.   
   
   
       12 . A method according to  claim 5  in which the compound concentration range in each step is different from the compound concentration range in (any of) the other step(s). 
   
   
       13 . A method for determining a value that allows the effect that a compound has on a target to be compared with the effect that another compound has on the target, which method comprises more than one step of:
 adding the compound, at different concentrations, to a flow of a target, wherein the compound concentration range in each step differs from the compound concentration range in any of the other steps.   
   
   
       14 . A method according to  claim 13  wherein the value is the IC x  value or EC x  value of a compound, wherein x is a percentage of the target activity. 
   
   
       15 . A method according to  claim 13 , wherein the highest compound concentration, lowest compound concentration or highest and lowest compound concentrations in each step differ(s) from the highest compound concentration, lowest compound concentration or highest and lowest compound concentrations, respectively, in any of the other steps. 
   
   
       16 . A method according to  claim 15 , wherein the highest and lowest concentrations in each step differ from the highest and lowest concentrations, respectively, in any of the other steps. 
   
   
       17 . A method according to  claim 5  in which there are three or more steps. 
   
   
       18 . A method according to  claim 5  in which there is overlap between the ranges used in at least two of the steps. 
   
   
       19 . A method according to  claim 18  in which the range in each step overlaps with the range in at least one other step. 
   
   
       20 - 24 . (canceled) 
   
   
       25 . A method for determining values for more than one compound, wherein each value is associated with one compound and allows the effect that said compound has on a target to be compared with the effect that another compound has on the target, wherein said values may optionally be IC x  values or EC x  values, wherein x is a percentage of the target activity, in which each compound is tested using the method of  claim 1 . 
   
   
       26 - 51 . (canceled) 
   
   
       52 . An apparatus adapted to be used to determine a value that allows the effect that a compound has on a target to be compared with the effect that another compound has on the target, which apparatus allows the addition of the compound at a concentration that continuously varies with time to a flow of the target. 
   
   
       53 - 60 . (canceled)